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为了在传统柴油机上实现同时降低NOx和碳烟排放的准均质预混合燃烧,采用在高压油泵后加热流经高压油管柴油的方法,在一台单缸柴油机上就高温柴油对发动机燃烧和排放的影响开展了台架试验研究.通过在进气中添加低比例的二氧化碳气体,对采用燃油加热实现柴油准均质混合气压燃燃烧过程进行了探索性研究;同时应用KIVA3V对高温燃油喷射对混合气形成的影响进行了模拟研究.结果表明:高温燃油能够促进喷雾雾化和预混合气的形成,且对应一个最佳的温度范围,通过适当增大供油提前角到上止点前32°,采用大流量的多孔喷嘴缩短喷射持续期,以及进气中添加少量二氧化碳等措施,可以实现直喷式柴油机准均质预混合燃烧,达到同时降低NOx和碳烟的目的.
In order to achieve a quasi-homogeneous pre-mixed combustion in a conventional diesel engine that reduces NOx and soot emissions at the same time, a method of heating and flowing a high pressure fuel pipe tube diesel after a high pressure oil pump is used to burn and discharge the engine in a single cylinder diesel engine The bench test was carried out.An exploratory research was carried out on the LPG combustion using quasi-homogeneous mixture of diesel fuel by adding a low proportion of carbon dioxide gas into the intake gas.At the same time, KIVA3V was used to simulate the high temperature fuel injection and mixing The results show that high temperature fuel can promote the formation of spray atomization and premixed gas, and corresponding to an optimal temperature range, by appropriately increasing the fuel supply advance angle to 32 ° before TDC , The use of large-flow multi-jet nozzle to shorten the injection duration, as well as a small amount of carbon dioxide into the intake and other measures can be achieved direct injection diesel homogeneous pre-mixed combustion to achieve the same purpose of reducing NOx and soot.